KR101480060B1 - Battery pack - Google Patents

Abstract

The present invention relates to a battery pack advantageous in integration and miniaturization, and more particularly, to a bare cell having a first polarity electrode terminal and a second polarity cap plate. And a battery protection circuit package electrically connected to the electrode terminal and the cap plate. Wherein the cap plate includes a concave portion to form a step downward, and at least a part of the battery protection circuit package is disposed in the concave portion.

Description

Battery pack

The present invention relates to a battery pack, and more particularly, to a battery pack to which a battery protection circuit package is applied.

Generally, batteries are used in mobile terminals such as mobile phones and PDAs. Lithium-ion batteries are the most widely used batteries in portable handsets, and they have overcharging and over-currents, and when the temperature rises due to the heat generation, the performance deteriorates as well as the risk of explosion. Therefore, a conventional battery may be provided with a protection circuit module for detecting and blocking overcharge, over-discharge, and over-current, or a battery protection circuit package for detecting overcharge, over-discharge, Can be used. However, there is a problem that the space occupied by a protection integrated circuit, a fieled effect transistor (FET), a resistor, a capacitor, and the like constituting the battery protection circuit package is too large, have.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a battery pack which is advantageous in integration and miniaturization. However, these problems are exemplary and do not limit the scope of the present invention.

A battery pack according to an aspect of the present invention is provided. The battery pack comprising: a bare cell having an electrode terminal of a first polarity and a cap plate of a second polarity; And a battery protection circuit package electrically connected to the electrode terminal and the cap plate. The cap plate includes a recess to form a step downward, and at least a portion of the battery protection circuit package is disposed in the recess.

In the battery pack, the electrode terminal and the battery protection circuit package may be located in the recess formed in the cap plate.

The battery pack may further include an upper case disposed on the bare cell and the battery protection circuit package and including an opening for exposing an external connection terminal of the battery protection circuit package.

The battery pack may further include an encapsulant for sealing and fixing at least a part of the battery protection circuit package by filling at least a part of the recess formed in the cap plate. The encapsulant may be configured to expose an external connection terminal of the battery protection circuit package and an upper surface of the encapsulant may be flush with an upper surface of the cap plate around the recess. The battery pack may further include an upper case disposed on the bare cell and the battery protection circuit package and including an opening for exposing an external connection terminal of the battery protection circuit package.

In the battery pack, the upper case may include at least one selected from the group consisting of aluminum, an alloy including aluminum, SUS, and resin.

Wherein the battery protection circuit package of the battery pack includes a plurality of leads separated from each other, the lead frame being bonded to the electrode terminals and the cap plate; And a battery protection circuit element mounted on the lead frame, the protection circuit element including a protection IC, a field effect transistor (FET), and at least one passive element. Wherein the passive element is arranged to connect at least a portion of the plurality of spaced apart leads, and wherein any two selected from the group consisting of the protection integrated circuit, the field effect transistor and the plurality of leads are electrically connected The battery protection circuit can be constructed without using a separate printed circuit board.

The lead frame of the battery pack may include a lead for a first internal connection terminal and a lead for a second internal connection terminal, the lead being connected to the electrode terminal and the cap plate, respectively; A lead for an external connection terminal, which is disposed between the lead for the first internal connection terminal and the lead for the second internal connection terminal and constitutes the external connection terminal; And an element mounting lead which is disposed between the leads for the first internal connection terminal and the leads for the second internal connection terminal and on which the battery protection circuit element can be mounted.

In the battery pack, the battery protection circuit package includes: a printed circuit board; And a battery protection circuit element having a protection IC, a field effect transistor (FET), and at least one passive element disposed on the printed circuit board.

According to some embodiments of the present invention as described above, it is possible to provide a battery pack advantageous in integration and miniaturization. Of course, the scope of the present invention is not limited by these effects.

1 is a cross-sectional view illustrating a portion of a battery pack according to an embodiment of the present invention.
2 is a circuit diagram of a battery protection circuit constituting a part of a battery protection circuit package applied to a battery pack according to an embodiment of the present invention.
3 is a diagram illustrating an arrangement structure of a stacked chip constituting a part of a battery protection circuit package applied to a battery pack according to an embodiment of the present invention.
4 is a plan view illustrating a structure of a lead frame constituting a part of a battery protection circuit package applied to a battery pack according to an embodiment of the present invention.
5 is a plan view illustrating an arrangement structure of a battery protection circuit element constituting a part of a battery protection circuit package applied to a battery pack according to an embodiment of the present invention.
6 is a diagram illustrating a battery protection circuit package applied to a battery pack according to an embodiment of the present invention.
FIGS. 7 and 8 are perspective views illustrating a process of combining a battery protection circuit package with a battery can in a battery pack according to an embodiment and a modified embodiment of the present invention.
9 is a perspective view illustrating the external appearance of a battery pack according to some embodiments of the present invention.
10 and 11 are a sectional view and a perspective view illustrating a part of a battery pack according to another embodiment of the present invention.
12 is a cross-sectional view illustrating a portion of a battery pack according to another embodiment of the present invention.
13 is a perspective view illustrating a PTC structure constituting a part of a battery protection circuit package in a battery pack according to another embodiment of the present invention.
14 is a diagram illustrating a battery protection circuit package in a battery pack according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments of the present invention are described in order to more fully explain the present invention to those skilled in the art, and the following embodiments may be modified into various other forms, It is not limited to the embodiment. Rather, these embodiments are provided so that this disclosure will be more thorough and complete, and will fully convey the concept of the invention to those skilled in the art. In the drawings, the thickness and size of each layer are exaggerated for convenience and clarity of explanation.

It is to be understood that throughout the specification, when an element such as a film, region or substrate is referred to as being "on", "connected to", "laminated" or "coupled to" another element, It is to be understood that elements may be directly "on", "connected", "laminated" or "coupled" to another element, or there may be other elements intervening therebetween. On the other hand, when one element is referred to as being "directly on", "directly connected", or "directly coupled" to another element, it is interpreted that there are no other components intervening therebetween do. Like numbers refer to like elements. As used herein, the term "and / or" includes any and all combinations of one or more of the listed items.

Although the terms first, second, etc. are used herein to describe various elements, components, regions, layers and / or portions, these members, components, regions, layers and / It is obvious that no. These terms are only used to distinguish one member, component, region, layer or section from another region, layer or section. Thus, a first member, component, region, layer or section described below may refer to a second member, component, region, layer or section without departing from the teachings of the present invention.

Also, relative terms such as "top" or "above" and "under" or "below" can be used herein to describe the relationship of certain elements to other elements as illustrated in the Figures. Relative terms are intended to include different orientations of the device in addition to those depicted in the Figures. For example, in the figures the elements are turned over so that the elements depicted as being on the top surface of the other elements are oriented on the bottom surface of the other elements. Thus, the example "top" may include both "under" and "top" directions depending on the particular orientation of the figure. If the elements are oriented in different directions (rotated 90 degrees with respect to the other direction), the relative descriptions used herein can be interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" include singular forms unless the context clearly dictates otherwise. Also, " comprise "and / or" comprising "when used herein should be interpreted as specifying the presence of stated shapes, numbers, steps, operations, elements, elements, and / And does not preclude the presence or addition of one or more other features, integers, operations, elements, elements, and / or groups.

Hereinafter, embodiments of the present invention will be described with reference to the drawings schematically showing ideal embodiments of the present invention. In the figures, for example, variations in the shape shown may be expected, depending on manufacturing techniques and / or tolerances. Accordingly, the embodiments of the present invention should not be construed as limited to the particular shapes of the regions shown herein, but should include, for example, changes in shape resulting from manufacturing.

1 is a cross-sectional view illustrating a portion of a battery pack according to an embodiment of the present invention. Referring to FIG. 1, a battery pack according to an embodiment of the present invention includes a bare cell 400 having a first polarity electrode terminal 410 and a second polarity cap plate 430.

The bare cell 400 may include an electrode assembly 405, a can 401 that receives the electrode assembly 405, and a cap assembly 450 that is provided on the opening of the can 401. The electrode assembly 405 includes a positive electrode plate 402 formed by applying a positive electrode active material to a positive electrode collector, a negative electrode plate 403 formed by applying a negative electrode active material to a negative electrode collector, and a negative electrode plate 403 interposed between the positive electrode plate 402 and the negative electrode plate 403. And a separator 404 for preventing shorting of the electrode plates 402 and 403 and enabling movement of lithium ions.

A positive electrode uncoated portion in which the positive electrode active material is not applied is formed on the positive electrode plate 402, and a negative electrode uncoated portion in which the negative electrode active material is not applied is formed on the negative electrode plate 403. A positive electrode tab 407 electrically connected to the cap plate 430 is bonded to the positive electrode uncoated portion and a negative electrode tab 408 electrically connected to the electrode terminal 410 may be bonded to the negative electrode uncoated portion. At this time, the positive electrode tab 407 and the negative electrode tab 408 may be bonded to the positive electrode uncoated portion and the negative electrode uncoated portion, for example, by welding.

The positive electrode collector may be a surface treated with carbon, nickel, titanium or silver on the surface of stainless steel, nickel, aluminum, titanium or an alloy thereof, aluminum or stainless steel, A porous material, a foaming agent, and the like. The positive electrode active material is a material capable of occluding or desorbing lithium ions, and may include at least one or more selected from a composite oxide with lithium, cobalt, manganese, and nickel.

Examples of the negative electrode collector include those obtained by surface-treating carbon, nickel, titanium, or silver on surfaces of stainless steel, nickel, copper, titanium or their alloys, copper or stainless steel, A porous material, a foaming agent, and the like. The negative electrode active material is a material capable of absorbing or desorbing lithium ions, and may be a carbon material such as crystalline carbon, amorphous carbon, carbon composite, or carbon fiber, lithium metal, lithium alloy, or the like.

The separator 404 is formed of, for example, a thermoplastic resin such as polyethylene (PE) or polypropylene (PP), and the surface of the separator 404 has a porous film structure. Such a porous membrane structure may become an insulating film by melting the separator 404 and clogging when the temperature of the inside of the battery rises near the melting point of the thermoplastic resin. By switching to the insulating film in this way, the lithium ion movement between the positive electrode plate 402 and the negative electrode plate 403 is interrupted, and furthermore the current can not flow, so that the temperature rise inside the battery can be stopped.

The can 401 may be formed of a metal material having an opened upper end and may receive the electrode assembly 405 and the electrolyte solution and may receive the insulation case 406 on the upper portion of the electrode assembly 405. [ As the metallic material, light and ductile aluminum, aluminum alloy, stainless steel, or the like can be used. If the can 401 is made of a metal material, it can be used as an electrode terminal because it can have polarity. The shape of the can 401 may be a square shape or an elliptical shape with a rounded corner, and the open upper end of the can 401 may be sealed or welded or thermally fused with the cap plate 430.

The cap assembly 450 includes an insulating case 406, a cap plate 430, a gasket 420, an electrode terminal 410, an insulating plate 412, a terminal plate 411, and an electrolyte injection stopper 415 . The insulating case 406 is located above the electrode assembly 405 inserted into the can 401 to prevent the electrode assembly 405 from flowing. Further, the insulating case 406 separates the positive electrode tab 407 and the negative electrode tab 408 from each other by a predetermined distance to prevent a short circuit.

The cap plate 430 is coupled to the opening of the can 401 so that the opening of the can 401 can be sealed and a through hole into which the gasket 420 and the electrode terminal 410 can be inserted can be formed. The cap plate 430 is provided with an electrolyte injection port for providing a passage for injecting an electrolyte into the can 401, and an electrolyte injection port 415 is hermetically sealed to the electrolyte injection port.

The cap plate 430 includes a recess 435 to form a step downward (e.g., in the Z direction in FIG. 1). That is, the cap plate 430 is formed with a level difference between the level of the bottom surface of the concave portion 435 and the level around the concave portion 435. The concave portion 435 may be understood as a hole, a cavity, a trench or the like depending on its shape and size. The cross-sectional shape of the recess 435 may have a polygonal, circular, oval or any amorphous shape. The concave portion 435 may have an open structure upward (for example, in the direction opposite to the Z direction in Fig. 1).

The gasket 420 is coupled to the through hole formed in the cap plate 430 and is formed of an insulating material to insulate the electrode terminal 410 of the first polarity and the cap plate 430 of the second polarity. The first polarity may be a cathode and the second polarity may be an anode, but the first polarity may be an anode and the second polarity may be a cathode if necessary. The central portion of the gasket 420 may form a hole to allow the electrode terminal 410 to be coupled. The electrode terminal 410 is inserted into the hole formed in the gasket 420 and is coupled to the cap plate 430. The lower end of the electrode terminal 410 is connected to the terminal plate 411 through the cap plate 430 do. The insulating plate 412 is located on the lower surface of the cap plate 430 and insulates the outer surface of the terminal plate 411 and forms a hole for connection between the electrode terminal 410 and the terminal plate 411. The terminal plate 411 is located on the lower surface of the insulating plate 412 and is made of a conductive material and connected to the electrode terminal 410 to form an electrical path.

Meanwhile, the battery pack according to an embodiment of the present invention includes a battery protection circuit package 300 that is electrically connected to the electrode terminal 410 and the cap plate 430. At least a portion of the battery protection circuit package 300 may be disposed within the recess 435. For example, the whole of the battery protection circuit package 300 may be disposed in the space in the recess 435. Further, the upper surface of the encapsulant 250 constituting the battery protection circuit package 300 may be flush with the upper surface of the cap plate 430 around the recess 435. If necessary, the electrode terminal 410 may be configured to be disposed in the concave portion 435 as well. On the other hand, the manner in which the battery protection circuit package 300 is bonded to the electrode terminal 410 and / or the cap plate 430 includes laser welding, resistance welding, soldering and a conductive adhesive (for example, A conductive tape, and a conductive tape.

A recess 435 is formed by using a part of the space 414 located between the insulating case 406 and the cap plate 430 and at least a part of the battery protection circuit package 300 is placed in the recess 435 So that the overall height of the battery pack can be reduced. Accordingly, the electrode assembly 405 in the battery pack can be increased in the ratio, thereby realizing a high-capacity battery pack.

Hereinafter, the configuration of the battery protection circuit package 300 will be described.

2 is a circuit diagram of a battery protection circuit constituting a part of a battery protection circuit package applied to a battery pack according to an embodiment of the present invention.

2, a battery protection circuit 10 applied to a battery protection circuit package 300 according to an embodiment of the present invention includes first and second internal connection terminals B + (P +, CF, P) for connecting to an electronic device (e.g., a portable terminal or the like) connected to the charger when charging, -). Here, the first external connection terminal P + and the third external connection terminal P- of the first to third external connection terminals P +, CF, and P- are for power supply and the other is an external connection terminal The second external connection terminal CF divides the battery and charges the battery according to the battery. In addition, a thermistor, which is a component for sensing the battery temperature during charging, can be applied, and other functions can be applied and utilized as a terminal.

The battery protection circuit 10 includes a connection structure of the dual FET chip 110, the protection integrated circuit 120, the resistors R1, R2 and R3, the varistor V1 and the capacitors C1 and C2 I have. The dual FET chip 110 includes a first field effect transistor (FET1) and a second field effect transistor (FET2) having a drain common structure. The protection IC 120 is connected to the first internal connection terminal B + which is the positive terminal of the battery through the resistor R1 and is connected to the first node n1 through the first node n1, A reference terminal (VSS terminal) serving as a reference for an operation voltage inside the protection integrated circuit 110, a detection terminal V-V for detecting charging / discharging and an over-current state, A discharge cutoff signal output terminal (DO terminal) for turning off the first field effect transistor FET1 in the overdischarged state, a charge cutoff signal output terminal (OFF terminal) for turning off the second field effect transistor FET2 in the overcharge state C0 terminal).

At this time, the inside of the protection integrated circuit 120 includes a reference voltage setting unit, a comparison unit for comparing a reference voltage with a charge / discharge voltage, an overcurrent detection unit, and a charge / discharge detection unit. Here, the criterion for determining the charging and discharging states can be changed to the specification (SPEC) required by the user, and the charging / discharging state is determined by recognizing the voltage difference of each terminal of the protection integrated circuit 120 according to the predetermined standard.

When the protection integrated circuit 120 reaches the over-discharge state at the time of discharging, the DO terminal becomes LOW to turn off the first field effect transistor FET1, and when the overcharge state is reached, the CO terminal becomes low The second field effect transistor FET2 is turned off when the overcurrent flows, and the first field effect transistor FET1 is turned off when the overcurrent flows.

The resistor R1 and the capacitor C1 serve to stabilize the fluctuation of the supply power source of the protection integrated circuit 120. [ The resistor R1 is connected between the VDD terminal of the protection integrated circuit 120 and the first node n1 which is the power supply V1 supply node of the battery and the capacitor C1 is connected between the VDD terminal of the protection integrated circuit and the VSS terminal Lt; / RTI > Here, the first node n1 is connected to the first internal connection terminal B + and the first external connection terminal P +. When the resistance R1 is increased, the detection voltage becomes higher due to the current penetrated into the protection integrated circuit 120 at the time of voltage detection, so that the value of the resistor R1 is set to an appropriate value of 1 K or less. Also, for stable operation, the value of the capacitor C1 has an appropriate value of 0.01 mu F or more.

And the resistors R1 and R2 become current limiting resistors when the high voltage charger or charger exceeding the absolute maximum rating of the protection integrated circuit 120 is connected upside down. The resistor R2 is connected between the V- terminal of the protection integrated circuit 120 and the second node n2 to which the source terminal S2 of the second field effect transistor FET2 is connected. Since the resistors R1 and R2 may cause power consumption, the sum of the resistance values of the resistors R1 and R2 is usually set to be larger than 1 K ?. If the resistance R2 is too large, the return may not occur after the overcharge cutoff, so that the value of the resistance R2 is set to a value of 10K or less.

The capacitor C2 is connected to the source terminal S1 of the first node n2 (or the third external connection terminal P-) and the first field effect transistor FET1 (or the VSS terminal, the second internal connection terminal B -)). The capacitor C2 does not significantly affect the characteristics of the battery protection circuit product, but is added for user's request or stability. The capacitor C2 is for stabilizing the system by improving the resistance to voltage fluctuation and external noise.

The resistor R3 and the varistor V1 are elements for ESD (Electrostatic Discharge) and surge protection and are connected in parallel to each other. The second external connection terminal CF and the second node n2 Or the third external connection terminal P-). The resistance of the varistor (V1) is lowered when an overvoltage occurs. When the overvoltage is generated, the resistance of the varistor (V1) is lowered, thereby minimizing circuit damage due to overvoltage.

In the present invention, a battery protection circuit package is constructed by packaging the battery protection circuit 10 shown in FIG. 2 including the external connection terminals P +, P-, and CF and the internal connection terminals B + and B- .

The protection circuit according to the embodiment of the present invention described above is an example, and the configuration, number, arrangement, etc. of the field effect transistor or the passive element can be appropriately modified in accordance with the additional function of the protection circuit.

3 is a diagram illustrating an arrangement structure of a stacked chip constituting a part of a battery protection circuit package applied to a battery pack according to an embodiment of the present invention.

3, the arrangement of the dual FET chip 110 and the protection integrated circuit 120 is such that the dual FET chip 110 and the protection integrated circuit 120 are stacked vertically, . For example, the dual FET chip 110 may have a structure in which the protection integrated circuit 120 is stacked on the upper surface, or the dual FET chip 110 may be disposed adjacent to the left or right side of the protection integrated circuit 120 .

The dual FET chip 110 includes a first field effect transistor and a second field effect transistor having a common drain structure, that is, two field effect transistors, and the external connection terminal includes a first gate terminal G1 And a first source terminal S1 and a second gate terminal G2 and a second source terminal S2 of the second field effect transistor on the upper surface of the dual FET chip 110. [ In addition, the common drain terminal D may be provided on the lower surface of the dual FET chip 110.

The protection integrated circuit 120 has a structure that is stacked on the upper surface of the dual FET chip 110. The protection integrated circuit 120 is stacked on a region (for example, a central portion) excluding a portion where external connection terminals on the dual FET chip 110 are disposed. At this time, an insulation layer may be disposed between the protection integrated circuit 120 and the dual FET chip 110, and the protection integrated circuit 120 and the dual FET chip 110 may be bonded with an insulating material. . Since the size of the dual FET chip 110 is larger than that of the protection integrated circuit 120, the configuration of stacking the protection integrated circuit 120 on the dual FET chip 110 is adopted.

After the protection integrated circuit 120 is stacked on the upper surface of the dual FET chip 110, the DO terminal DO of the protection integrated circuit 120 is electrically connected to the first gate terminal G1 via a wire or a wiring And the CO terminal (CO) of the protection integrated circuit 120 is electrically connected to the second gate terminal G2 through a wire or a wire. The connection structure of the remaining terminals will be described later. The protection integrated circuit 120 and the dual FET chip 110 having the above-described laminated structure will be collectively referred to as a laminated chip 100a.

In a battery protection circuit package applied to a battery pack according to an embodiment of the present invention, a protection integrated circuit 120 having a laminated structure and a laminated chip 100a of a dual FET chip are introduced to be mounted on a lead frame It is possible to reduce the area and thereby realize the miniaturization or the high capacity of the battery.

The battery protection circuit package 300 may include a printed circuit board and a battery protection circuit element disposed on the printed circuit board. Alternatively, the battery protection circuit package 300 may include a lead frame and a battery protection circuit element disposed on the lead frame. Here, the battery protection circuit element may include a protection integrated circuit, a field effect transistor, and at least one passive element. In the embodiments of the present invention, the lead frame may be divided into a structure in which the lead terminals are patterned on the metal frame, and a structure and thickness of the lead frame are different from those of the printed circuit board on which the metal wiring layer is formed. Hereinafter, a package for disposing the battery protection circuit element on the lead frame will be described.

FIG. 4 is a plan view illustrating a structure of a lead frame constituting a part of a battery protection circuit package applied to a battery pack according to an embodiment of the present invention, FIG. 5 is a sectional view of a battery pack according to an embodiment of the present invention Fig. 7 is a plan view illustrating an arrangement structure of battery protection circuit elements constituting a part of the battery protection circuit package.

4 and 5, in the battery protection circuit package applied to the battery pack according to the embodiment of the present invention, the lead frame 50 includes a first internal connection terminal region A1, an external connection terminal region A2, The device area A3, the chip area A4, and the second internal connection terminal area A5 are sequentially arranged. The protection circuit region is disposed between the external connection terminal region A2 and the second internal connection terminal region A5. The arrangement order of the element region A3 and the chip region A4 may be variously changed.

The first internal connection terminal region A1 and the second internal terminal region A5 are provided at both edge portions of the package and are connected to the cap assembly 450 constituting the bare cell 400, (B +) for functioning as a first internal connection terminal and a lead (B-) for a second internal connection terminal functioning as a second internal connection terminal, respectively.

The external connection terminal region A2 is connected to the first to third external connection terminal leads P +, P +, which are adjacent to the first internal connection terminal region A1 and are lead terminals for a plurality of external connection terminals functioning as a plurality of external connection terminals, CF, and P-) are sequentially arranged. The arrangement order of the first to third external connection terminal leads (P +, CF, P-) may be variously changed. Here, the first external connection terminal lead (P +) and the first internal connection terminal lead (B +) are connected to each other. That is, the first internal connection terminal lead B + may extend from the first external connection terminal lead P + or the first external connection terminal lead P + may extend from the first internal connection terminal lead B + As shown in FIG.

The element region A3 is for arranging a plurality of passive elements R1, R2, R3, C1, C2, and V1 constituting a battery protection circuit. For example, The sixth passive element leads L1, L2, L3, L4, L5, and L6 are disposed. For example, the first to third passive element leads L 1, L 2 and L 3 may have a sequential arrangement structure on the upper side of the element region A 3, and the fourth to sixth passive element leads L 4, L5, and L6 may be disposed on the lower side of the element region A3.

For example, the first passive element lead L1 is arranged to have a constant size in the element region A3 adjacent to the external connection terminal region A2, and the second passive element lead L2 is arranged in the element region A3 adjacent to the external connection terminal region A2, And is disposed at a predetermined size adjacent to the lead L1. The third passive element lead L3 is disposed in the element region A3 adjacent to the chip area A4 with a predetermined size adjacent to the second passive element lead L2. The fourth passive element lead L4 is arranged in a predetermined size in the element region A3 adjacent to the external connection terminal region A2 and the fifth passive element lead L5 and the sixth passive element lead L6 Is disposed adjacent to the fourth passive element lead L1 in such a manner that the fifth passive element lead L5 surrounds the sixth passive element lead L6.

The chip area A4 is adjacent to the element area A3 and is a region in which the protection integrated circuit and the dual FET chip constituting the battery protection circuit are disposed. The die pad DP for mounting the multilayer chip 100a is disposed . The die pad DP can be electrically connected to the common drain terminal of the dual FET chip 110 constituting the multilayer chip 100a and functions as an external connection terminal in order to expose it in the packaging of a subsequent process, Can be improved.

4 and 5, a plurality of passive elements R1, R2, R3, C1, C2, and V1 and a multilayer chip 100a are disposed on the lead frame of FIG. 4, Thereby constituting an equivalent circuit shown in Fig.

The multilayer chip 100a is mounted on the die pad DP of the chip area A4 and the reference voltage terminal VSS of the protection integrated circuit 120 constituting the multilayer chip 100a is connected to the first field effect transistor And the third passive element lead L3 is electrically connected by wire bonding.

The voltage VDD applied to the protection integrated circuit 120 for applying the charging voltage and the discharging voltage and the terminal VDD for sensing the battery voltage are electrically connected to the second passive element lead L2 through wire bonding or the like, The sensing terminal V- for sensing charging / discharging and overcurrent states in the integrated circuit 120 is electrically connected to the sixth passive element lead L6 through wire bonding.

The source terminal S1 of the first field effect transistor is electrically connected to the third passive element lead L3 through wire bonding or the like and the source terminal S2 of the second field effect transistor is electrically connected to the fifth passive element lead (L5) through wire bonding or the like.

Next, the first passive element lead L1 and the first external connection terminal lead P + are electrically connected through wire bonding or the like, and the third passive element lead L3 and the second internal connection terminal The leads (B-) are electrically connected by wire bonding or the like. The fourth passive element lead L4 is electrically connected to the second external connection terminal lead CF through wire bonding and the fifth passive element lead L5 is electrically connected to the third external connection terminal lead L3, And is electrically connected through wire bonding or the like. The first resistor R1 of the plurality of passive elements is disposed between the lead L1 for the first passive element and the lead L2 for the second passive element, The second passive element R2 is disposed between the fifth passive element lead L5 and the sixth passive element lead L6.

The third resistor R3 constituting the surge protection circuit among the plurality of passive elements is disposed between the fourth passive element lead L4 and the fifth passive element lead L5, The first capacitor C1 is disposed between the second passive element lead L2 and the third passive element lead L3 and the second one of the plurality of passive elements C2 is connected to the third passive element C2, And is disposed between the lead L3 and the fifth passive element lead L5. The varistor V1 constituting the surge protection circuit among the plurality of passive elements is formed in parallel with the third resistor R3 so that the fourth passive element lead L4 and the fifth passive element lead L5.

Meanwhile, in other embodiments of the present invention, the circuit diagram of the battery protection circuit shown in FIG. 2 and the protection circuit structure 200a shown in FIG. 5 implementing the same may be variously modified, . ≪ / RTI >

For example, in a modified first structure, a first field effect transistor (FET1), a second field effect transistor (FET2), and a protection integrated circuit may be provided integrated in one chip. The integrated chip can be mounted on the lead frame 50 in the form of a flip chip. The flip chip is advantageous in that the external terminal portion is soldered to a lead or the like which requires electrical connection without requiring additional wire bonding, thereby improving electrical conductivity compared to wire bonding, lowering the production cost and simplifying the process, This has the advantage of reducing the volume occupied.

Also, for example, in the modified second structure, the first field effect transistor (FET1) and the second field effect transistor (FET2) are not implemented as a dual FET chip on the lead frame 50, . In this case, in order to electrically connect the drain of the first field effect transistor (FET1) and the drain of the second field effect transistor (FET2) to each other, a conductive plate connecting the lower faces of the lead frame 50 Can be deployed.

The battery protection circuit module package 300 is formed as shown in FIG. 6 through the process of molding the protection circuit structure 200a shown in FIG. 5 or the deformed structures described above into the sealing material 250 do. The encapsulant 250 may comprise, for example, an epoxy molding compound (EMC).

FIG. 6A is a bottom view of a battery protection circuit package 300 according to an embodiment of the present invention, and FIG. 6B is a top view of a battery protection circuit package 300. For example, the lower surface of the battery protection circuit package 300 corresponds to the upper surface 50a of the lead frame 50, and the upper surface of the battery protection circuit package 300 corresponds to the lower surface of the lead frame 50 50b. The lower surface of the battery protection circuit package 300 may be opposed to the cap plate 430, for example, shown in Fig.

In the battery protection circuit package 300 according to the embodiment of the present invention, the external connection terminals P +, CF and P- are exposed on the upper surface and the first internal connection terminal B + And the internal connection terminal B- is exposed. Here, the upper surface of the package 300 may be packaged so as to further expose the lower surface of the die pad DP (the surface opposite to the surface on which the laminated chip 100a is mounted) according to heat radiation or other necessity. At least one of the first internal connection terminal lead B + and the second internal connection terminal lead B- may be bent in a gull-form form. For example, the lead (B +) for the first internal connection terminal may be bent in a gull-form form to compensate for a step between the upper surface of the electrode terminal 410 and the bottom surface of the recess 435 have.

In the battery protection circuit package applied to the battery pack according to the embodiment of the present invention, the package 300 including the lead frame 50 may constitute a battery protection circuit without using a separate printed circuit board. At least one passive element is arranged to connect at least a portion of the plurality of spaced leads, and at least one of the field effect transistor 110, the protection integrated circuit 120 and the plurality of leads And by providing an electrical connecting member for electrically connecting the two. The electrical connecting member may include a bonding wire or a bonding ribbon.

A significant advantage that the process of designing and manufacturing the lead frame 50 for constituting the battery protection circuit can be simplified because the circuit is constituted by disposing the electrical connecting member such as the bonding wire or the bonding ribbon on the lead frame 50 . If the electrical connecting member described in the embodiments of the present invention is not adopted in the implementation of the battery protection circuit component, the configuration of the plurality of leads constituting the lead frame 50 becomes very complicated, It may not be easy to effectively provide the information.

The protection integrated circuit 120 and / or the field effect transistor 110 are not inserted and fixed in the form of a semiconductor package on the lead frame 50, but may be mounted on the lead frame 50 by Surface Mounting Technology. , In the form of a chip die, which is sawed on a wafer that is not sealed with a separate encapsulation material. Here, a chip die is a chip die, which is formed by performing a sowing process on a wafer on which a plurality of array structures (for example, a protection integrated circuit or a field effect transistor) is formed, ≪ / RTI > That is, when at least one selected from the group consisting of the protection integrated circuit and the field effect transistor (FET) is mounted on the lead frame 50, the lead frame 50 is mounted in a state in which it is not sealed with a separate sealing material, Since the protection integrated circuit and the field effect transistor are sealed by the insulating layer 250, the process of forming the sealing material can be performed only once when the battery protection circuit package 300 is implemented. On the other hand, when the protection integrated circuit and / or the field effect transistor are separately inserted into the printed circuit board (PCB) and fixed or mounted, a single molding process is first required for each component and fixed on the printed circuit board Since another molding process is additionally required for each component mounted after mounting, the manufacturing process may be complicated and the manufacturing cost may increase.

FIGS. 7 and 8 are perspective views illustrating a process of combining a battery protection circuit package with a battery can in a battery pack according to an embodiment and a modified embodiment of the present invention, and FIG. 9 is a perspective view of a battery pack according to some embodiments of the present invention FIG. 2 is a perspective view illustrating the external shape of the battery pack.

7 to 9, the battery protection circuit package 300 is inserted between the upper surface of the bare cell 400 shown in FIG. 1 and the upper case 500 to form a battery pack (not shown) 600). The upper case 500 may include at least one selected from the group consisting of aluminum, an alloy including aluminum, stainless steel (SUS), and resin. The upper case 500 is formed with an opening 550 which is a through hole at a corresponding portion of the upper case 500 so that the external connection terminals P +, CF and P- of the battery protection circuit package 300 are exposed. The rim of the upper case 500 may be joined to the can constituting the bare cell 400, for example, by laser welding or mechanical fastening with a bolt. The battery pack 600 is generally understood as a battery inserted into a cell phone, a terminal, or the like.

The lead B + for the first internal connection terminal is electrically connected to the cap plate 430 and the lead B- for the second internal connection terminal is electrically connected to the electrode terminal 410. In this case, the length of the lead frame 50 may correspond to the length (L / 2) from one end of the cap plate 430 to the electrode terminal 410. According to this embodiment, since the battery protection circuit package 300 is mounted using only the one side region with respect to the electrode terminal 410 located at the center of the cap plate 430, the battery pack can be downsized or can be made to have a high capacity . For example, by forming a cell in the remaining one side region with respect to the electrode terminal 410 to increase the capacity of the battery or disposing a chip or the like having another additional function, it can contribute to miniaturization of an application product having such a battery.

Referring to FIG. 7, the recess 435 in which the battery protection circuit package 300 is disposed includes a space defined by a bottom surface and a side surface. The side defining the recess 435 may be composed of two side surfaces that are perpendicular to the y-axis and oppose each other, and two sides that are perpendicular to the x-axis and oppose each other. The concave portion 435 may have an open structure in an upward direction (e.g., the opposite direction to the z direction). Since the side surface of the concave portion 435 is not open, the effect of facilitating the filling of the space in the concave portion 435 with the sealing material 555 in Fig. 10 can be expected.

Referring to FIG. 8, the recess 435 in which the battery protection circuit package 300 is disposed includes a space defined by a bottom surface and a side surface. The side defining the recess 435 may be composed of two sides perpendicular to the x-axis and facing each other. The recessed portion 435 may have an open structure in an upward direction (for example, the opposite direction to the z direction) and a lateral direction (for example, the y direction). The effect of facilitating the process of inserting and disposing the battery protection circuit package 300 in the concave portion 435 can be expected since the side of the concave portion 435 is open.

The step of filling at least a part of the concave portion 435 with the sealing material may be selectively performed before the upper case 500 is bonded. That is, after the battery protection circuit package 300 is bonded to the recess 435, the upper case 500 is connected to the can (not shown) constituting the bare cell 400 without filling at least a part of the recess 435 with the sealing material 401). Alternatively, after the battery protection circuit package 300 is connected to the recess 435, at least a part of the recess 435 may be filled with an encapsulating material and the upper case 500 may be formed of the bare cell 400 The can 401 can be joined to the can 401.

10 and 11 are a sectional view and a perspective view illustrating a part of a battery pack according to another embodiment of the present invention.

10 and 11, at least a portion of the battery protection circuit package 300 may be sealed while filling at least a part of the recessed portion 435 formed in the cap plate 430 with the sealing material 555 . For example, the encapsulant 555 is configured to expose the external connection terminals P +, CF, P- of the battery protection circuit package 300, and the upper surface of the encapsulant 555 is covered by the recesses 435 The upper surface of the cap plate 430 may be flush with the upper surface of the cap plate 430. In this case, the battery pack according to another embodiment of the present invention can be realized without further joining the upper case 500 as shown in FIG. Of course, the battery pack shown in FIG. 9 may be implemented by joining the upper case 500 on the structure shown in FIG.

12 is a cross-sectional view illustrating a portion of a battery pack according to another embodiment of the present invention. 12, in a battery pack according to another embodiment of the present invention, unlike FIG. 1, a configuration in which the electrode terminal 410 is not located in the concave portion 435 forming a step on the cap plate 430 / RTI > Since the structure of the electrode terminal 410 and the gasket 420 having a complicated structure is not located in the recess 435, it is easy to realize the recess 435. It is also possible to form the recess 435 by using a part of the space 414 located between the insulating case 406 and the cap plate 430 and to dispose at least part of the battery protection circuit package 300 in the recess 435 The overall height of the battery pack can be reduced. Accordingly, the electrode assembly 405 in the battery pack can be increased in the ratio, thereby realizing a high-capacity battery pack.

Since only the electrode terminal 410 is located outside the concave portion 435, only a part of the battery protection circuit package 300 is located in the space in the recess 435 and the remaining portion of the battery protection circuit package 300 The battery pack structure shown in FIG. 11 is difficult to implement and the structure of the battery pack shown in FIG. 9 can finally be realized.

Hereinafter, a PTC structure that can be additionally bonded to the battery protection circuit package 300 of some embodiments of the present invention described above will be described.

FIG. 13 is a perspective view illustrating a PTC structure constituting a part of a battery protection circuit package in a battery pack according to another embodiment of the present invention. FIG. 14 is a perspective view illustrating a battery protection circuit in a battery pack according to another embodiment of the present invention. Fig.

Referring to FIGS. 13 and 14, a battery protection circuit package according to another embodiment of the present invention includes a PTC structure 350. The PTC structure 350 includes a PTC device 310 and a metal layer 320 attached to a first surface of the PTC device 310. The PTC device 350 includes an upper surface and a lower surface of the PTC device 310, (330, 340) attached to a second side of the first side (330). The metal layer 320 is bonded to one of the leads for the first internal connection terminal B + and the second internal connection terminal lead B-, and the connection members 330 and 340 are connected to the electrode terminals Lt; RTI ID = 0.0 > 410 < / RTI > For example, the metal layer 320, the connecting members 330 and 340 and / or the lead frame 50 may be made of nickel, copper, nickel plated copper or other metal. The metal layer 320 is electrically connected to one of the leads for the first internal connection terminal B + and the second internal connection terminal B- by laser welding, resistance welding, soldering, and a conductive adhesive For example, conductive epoxy), and conductive tape.

The PTC (Positive Temperature Coefficient) element 310 can be formed, for example, by dispersing conductive particles in a crystalline polymer. Therefore, the PTC device 310 becomes a passage through which current flows between the metal layer 320 and the conductive connecting members 330 and 340 at a temperature below the set temperature. However, when the temperature exceeds the set temperature due to the occurrence of the overcurrent, the crystalline polymer swells and the resistance between the conductive particles dispersed in the crystalline polymer is separated and the resistance is rapidly increased. Accordingly, the flow of current between the metal layer 320 and the conductive connecting members 330 and 340 is cut off or the flow of current is reduced. Since the flow of the current can be cut off by the PTC device 310, the PTC device 310 serves as a safety device for preventing the battery from rupturing. When the temperature is lower than the set temperature again, the PTC element 310 shrinks the crystalline polymer and restores the connection between the conductive particles, so that the current flows smoothly.

The lead frame 50 constituting the battery protection circuit package 300 is electrically connected to the electrode terminal 410 via the PTC structure. For example, the lead B- for the second internal connection terminal of the lead frame 50 may be electrically connected to the electrode terminal 410 of the battery bare cell via the PTC structure 350. That is, the lead B- for the second internal connection terminal of the lead frame 50 is bonded to the metal layer 320 and is electrically connected to the electrode (not shown) of the battery bare cell via the conductive connecting members 330 and 340 via the PTC element 310. [ And is electrically connected to the terminal 410. In this case, the metal layer 320 is defined within the upper surface of the PTC device 310, and the connecting members 330 and 340 are electrically connected to the electrode terminal 410 of the battery bare cell on the lower surface of the PTC device 310, As shown in FIG. The connecting members 330 and 340 of the PTC structure are connected to the first connecting member 330 and the first connecting member 330 attached to one surface of the PTC device 310 and extend to the electrode terminals 410 of the battery bare cell The second connecting member 340 may be formed of a metal plate. The second connection member 340 has a proper level to be able to be connected to the electrode terminal 410 so that the portion where the first connection member 330 and the second connection member 340 are connected can be bent. The second connection member 340 is electrically connected to the electrode terminal 410 of the battery bare cell by laser welding, resistance welding, soldering, and a conductive adhesive (for example, conductive epoxy) Can be joined in one manner.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

300: Battery protection circuit package
400: Bare cell
410: Electrode terminal
430: cap plate
500: upper case
555: Encapsulation material
600: Battery pack

Claims (10)

A bare cell having an electrode terminal of a first polarity and a cap plate of a second polarity; And
And a battery protection circuit package that is electrically connected to the electrode terminal and the cap plate,
Wherein the cap plate includes a recess to form a step downwardly, at least a portion of the battery protection circuit package is disposed within the recess,
Wherein the electrode terminal and the battery protection circuit package are located in the recess formed in the cap plate,
The battery protection circuit package
A lead frame including a plurality of spaced leads, the lead frame being bonded to the electrode terminal and the cap plate; And
And a battery protection circuit element mounted on the lead frame, the protection circuit element including a protection integrated circuit, a field effect transistor, and at least one passive element,
Wherein the passive element is arranged to connect at least a portion of the plurality of spaced apart leads, and wherein any two selected from the group consisting of the protection integrated circuit, the field effect transistor and the plurality of leads are electrically connected And a battery protection circuit is formed without using a separate printed circuit board. delete The method according to claim 1,
And an upper case disposed on the bare cell and the battery protection circuit package and including an opening exposing an external connection terminal of the battery protection circuit package. The method according to claim 1,
And a sealing member sealingly fixing at least a part of the battery protection circuit package by filling at least a part of the recess formed in the cap plate. 5. The method of claim 4,
Wherein the sealing material is configured to expose an external connection terminal of the battery protection circuit package and the upper surface of the sealing material is flush with the upper surface of the cap plate around the recess. 5. The method of claim 4,
And an upper case disposed on the bare cell and the battery protection circuit package and including an opening exposing an external connection terminal of the battery protection circuit package. The method according to claim 3 or 6,
Wherein the upper case includes at least one selected from the group consisting of aluminum, an alloy including aluminum, SUS, and a resin. delete The method according to claim 1,
The lead frame includes:
A lead for a first internal connection terminal and a lead for a second internal connection terminal, the lead being connected to the electrode terminal;
A lead for an external connection terminal, which is disposed between the lead for the first internal connection terminal and the lead for the second internal connection terminal and constitutes an external connection terminal; And
An element mounting lead which is disposed between the lead for the first internal connection terminal and the lead for the second internal connection terminal and on which the battery protection circuit element can be mounted;
. delete

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